Visualisation of Ontologies and Large Scale Graphs

Image via Wikipedia

For a whole number of reasons, I am currently looking into the visualisation of large-scale graphs and ontologies and to that end, I have made some notes concerning tools and concepts which might be useful for others. Here they are:

Visualisation by Node-Link and Tree

jOWL: jQuery Plugin for the navigation and visualisation of OWL ontologies and RDFS documents. Visualisations mainly as trees, navigation bars.

OntoViz: Plugin into Protege…at the moment supports Protege 3.4 and doesn’t seem to work with Protege 4.

IsaViz: Much the same as OntoViz really. Last stable version 2004 and does not seem to see active development.

NeOn Toolkit: The Neon toolkit also has some visualisation capability, but not independent of the editor. Under active development with a growing user base.

OntoTrack: OntoTrack is a graphical OWL editor and as such has visualisation capabilities. Meager though and it does not seem to be supported or developed anymore either…the current version seems about 5 years old.

Cone Trees: Cone trees are three-dimensional extensions of 2D tree structures and have been designed to allow for a greater amount odf information to be visualised and navigated. Not found any software for download at the moment, but the idea is so interesting that we should bear it in mind. Examples are here, here and the key reference is Robertson, George G. and Mackinlay, Jock D. and Card, Stuart K., Cone Trees: animated 3D visualizations of hierarchical information, CHI ’91: Proceedings of the SIGCHI conference on Human factors in computing systems, 1991, ISBN = 0-89791-383-3, pp.189-194. (DOI here)

PhyloWidget: PhyloWidget is software for the visualisation of phylogenetic trees, but should be repurposable for ontology trees. Javascript – so appropriate for websites. Student project as part of the Phyloinformatics Summer of Code 2007.

The JavaScript Information Visualization Toolkit: Extremely pretty JS toolkit for the visualisation of graphs etc…..Dynamic and interactive visualisations too…just pretty. Have spent some time hacking with it and I am becoming a fan.

Welkin: Standalone application for the visualisation of RDF graphs. Allows dynamic filtering, colour coding of resources etc…

Three-Dimensional Visualisation

Ontosphere3D: Visualisation of ontologies on 3D spheres. Does not seem to be supported anymore and requires Java 3D, which is just a bad nightmare in itself.

Cone Trees (see above) with their extension of Disc Trees (for an example of disc trees, see here

3D Hyperbolic Tree as exemplified by the Walrus software. Originally developed for website visualisation, results in stunnign images. Not under active development anymore, but source code available for download.

Cytoscape: The 1000 pound gorilla in the room of large-scale graph visualization. There are several plugins available for interaction with the Gene Ontology, such as BiNGO and ClueGO. Both tools consider the ontologies as annotation rather than a knowledgebase of its own and can be used for the identification of GO terms, which are overrepresented in a cluster/network. In terms of visualisation of ontologies themselves, there is there is the RDFScape plugin, which can visualize ontologies.

Zoomable Visualisations

Jamabalaya – Protege Plugin, but can also run as a browser applet. Uses Shrimp to visualise class hierarchies in ontologies and arrows between boxes to represent relationships.

CropCircles (link is to the paper describing it): CropCircles have been implemented in the SWOOP ontology editor which is not under active development anymore, but where the source code is available.

Information Landscapes – again, no software, just papers.

Exploring Chemical Space with GDB – Jean Louis Raymond (University of Bern)

Image via Wikipedia

(These are live notes from a talk Prof Reymond gave at EBI today)

The GDB Database

GDB = Generated Database (of Molecules)

The Chemical Universe Project – how many small molecules are possible?

GDB was put together by starting from graphs –  in this case the graphs were hydrocarbons and used GENG software to elaborate all possible graphs (after predefining which graphs are chemically reasonable and incorporating bonding informatation etc.) Then place atoms, enumerate, get combinatorial explosion of compounds and apply filters to remove chemical immpossibility: result couple of billion compounds.

 

Some choices restricting diversity: no allenes, no DB at bridgeheads etc, problematic heteroatom constellations (did not consider peroxides), hydrolytically labile functional groups.

In general – number of possible molecules increases exponentially with increasing number of nodes.

Showing that the molecular diversity increases with linear open carbon skeletons – cyclic graphs have fewer substitution possibilities. Chiral compounds offer more diversity than non-chiral ones.

 

GDB Website

 

Now talking about GDB13:

removed fluorine, introduced sulphur, filtered for molecules with “too many” heteroatoms – due to synthetic difficulties and the fact they may be of lesser interest to medchem.

Now showing statistical analysis of molecular types in GDB. 95% of all marketed drugs violate at least two Lipinski Rules. All molecules in the GDB13 are Lipinski conformant.

Use case: take known drug and find isomers. Aspirin has approx 180 compounds similar to Aspirin by Tanimoto score > 0.7 similarity. Points out that any of these molecules may not have been imagined by chemists.

 

GDB15 is just out – corrected some bugs, eliminated enol ethers (due to quick hydrolysis), optimized CPU usage…approx 26 billion molecules, 1.4 Tb – counting them takes a day)

 

Applications of the Database – mainly GDB 11

Use case: Glutamatergic Synapse Binding

used Bayesian classifier trained with known actives and then used that to retrieve about 11000 molecules from GDB11. This was followed by high throughput docking – selected 22 compounds for lab testing. Enrichment of glycine-containing compounds. Now showing some activity data for selected compounds.

Use case: Glutamate Transporter: applied certain structural selection criteria to database molecules to obtain a subset of approx 250 k compounds. Again followed by HT docking. Now showing syntheses of some selected candidate structures together with screening data.

 

“Molecular Quantum Numbers”

Classification system for large compound databases. Draws analogy to periodic table: classification system for elements. We do not have something like this for molecules. Define features for molecules: atom types, bond types, polarity, topology……42 categories in total. Now examines ZINC database against these features: can show that there are common features for molecules occupying similar categories.PCA analysis: first 2 PCs cover 70% of diversity space: first PC includes molecular weight…2D representations considered to be acceptable. PCA also shows nice grouping of molecules by number of cycles

Same analysis for GDB 11: first PCs now mainly account for molecular flexibility, polarity (doesn’t contain many rings due to atom limitation).

Analysis for PubChem – difficult to discover information at the moment.

Was on the cover of ChemMedChem this November.

Shows examples of fishing our structural motive analogies for given molecular motives.

SWAT4LS2009 – James Eales: Mining Semantic Networks of Bioinformatics eResources from Literature

eResource Annotations could help with

• making better choices: which resource is best?
• which is available?
• reduce curation
• help with service discovery

Approach: link bioinformatics resources using semantic descriptors generated from text mining….head terms for services can be used to assign services to types..e.g. applications, data sources etc.

SWAT4LS2009 – Michael Schroeder: Predicton of Drug Target Interactions from Literature by Context Similarity

Typical researcher spends 12.4 hours a week searching for information. Why not use Google? ‘Cause Google is not semantic.

Go PubMed – Filter PubMed contents against all the terms in the Gene Ontology. If you use simple categorisation for information retrieval potentially increase search burden due to compartmentalisation. However works the other way round too…useful filtering.

Showing some examples of faceted browsing of PubMed content and systematic drilldown into search results. Not easy to blog, but literature exploration in this way is always fascinating. Examples include the analysis of research trends, networks of colaborators etc..new tool in Go PubMed also allows the discovery of indirect links or inferred links.

Have developed a similar system for the web: Go Web (works on the top yahoo search results).

Remarks on Ontology Generation: have developed a plugin for OBO Edit…search for term and plugin makes suggestions for terms that might be included in new ontologies. Points out terms in existing ontologies. Also helps with the generation of definitions for terms…wow this is extremely useful in SO many ways….

Now let’s talk about drugs and targets….

Try and mine for gene mentions in text…find a gene term and then use context to decide what it is we are talking about. Once gene has found look for statistically significant co-occurences. The results have been made available in GoGene. Again can do bibliometric trend analysis – genes are ranked by community interest.

From drugs to genes..what is the link between a gene and a drug using context profiles: what are the disease terms related to a given drug…then to genes.

Gotta stop blogging…enjoying this talk far too much…….

SWAT4LS2009 – Linking Open Drug Data to Cheminformatics abd Proteochemometrics

Image via Wikipedia

(Notes frm the presentation as it happens)

Knowledge is not uni or bivariate, but we think of it as such: this leads to information loss.

Naming things: showing example of a trivial name, an IUPAC systematic name and an InChI and points out that these have different information content.

Points out scaling problem: drug discovery is multivariate and happens in a space of approx 10¹⁶ molecules (all molecules that are feasible and thought to be drug-like). Information loss occurs as you traverse this space backwards and forwards.

Now talks about molecular information in RDF: http://rdf.openmolecules.net for the provision of derefernceable URIs for molecules….and plugging the Chemistry Development Kit (CDK) as a means for cnverting between multiple representations of a molecule. Now moves on to Bioclipse as an integrating tool that allows chemical data transformations and the tracking of vwhy these transformations occur (version-controllable scripts to drive Bioclipse).

RDF extension to bioclipse: local RDF storage, read/write RDF, run SPARQL queries and extract RDF from XHTTML/RDFa.

Now shows an example of the expression of the CDK data model using ontologies but no details. Brief mention of his recent descriptor ontology.

SWAT4LS2009 – Sonja Zillner: Towards the Ontology Based Classification of Lymphoma Patients using Semantic Image Annotation

(Again, these are notes as the talk happens)

This has to do with the Siemens Project Theseus Medico – Semantic Medical Image Understanding (towards flexible and scalable access to medical images)

Different images from many different sources: e.g. X-ray, MRI etc…use this and combine with treatment plans, patient data etc and integrate with external knowledge sources.

Example Clinical Query:” Show me theCT scans and records of patiens with a Lymph Node enlargement in the neck area” – at the moment query over several disjoint systems is required

Current Motivation: generic and flexible understanding of images is missing
Final Goal: Enhance medical image annotations by integrating clinical data with images
This talk: introduce a formal classification system for patients (ontological model)

Used Knowledge Sources:

• Ann-Arbor Staging System – particularly suitable for lymphoma patients
• RadLex
• Foundational Model of Anatomy
• Semantic Image Annotation

Requirements of the Ontological Model

• Capture the rationale of the Ann Arbor Staging system
• Integrate external ontologies
• Ontology must describe the patient record

Now showing an example axiomatisation for the counting and location of lymphatic occurences and discussses problems relating to extending existing ontologies….

Now talking about annotating patient records: typical problems are abbreviations, clinical codes, fragments of sentences etc…difficult for NLP people to deal with….

Now showing detailed patient example where application of their classification system led to reclassification of patient in terms of staging system.

SWAT4LS2009 – Keynote Alan Ruttenberg: Semantic Web Technology to Support Studying the Relation of HLA Structure Variation to Disease

(These are live-blogging notes from Alan’s keynote…so don’t expect any coherent text….use them as bullt points to follow the gist of the argument.)

The Science Commons:

• a project of the Creative Commons
• 6 people
• CC specializes CC to science
• information discovery and re-use
• establish legal clarity around data sharing and encourage automated attribution and provenance

Semantic Web for Biologist because it maximizes value o scientific work by removing repeat experimentation.

ImmPort Semantic Integration Feasibility Project

• Immport is an immunology database and analysis portal
• Goals:metaanalysis
• Question: how can ontology help data integration for data from many sources

Using semantics to help integrate sequence features of HLA with disorders
Challenges:

• Curation of sequence features
• Linking to disorders
• Associating allele sequences with peptide structures with nomenclature with secondary structure with human phenotype etc etc etc…

Talks about elements of representation

• pdb structures translated into ontology-bases respresentations
• canonical MHC molecule instances constructed from IMGT
• relate each residue in pdb to the canonical residue if exists
• use existing ontologies
• contact points between peptide and other chains computed using JMOL following IMGT. Represented as relation between residue instances.
• Structural features have fiat parts

Connecting Allele Names to Disease Names

• use papers as join factors: papers mention both disease and allele – noisy
• use regex and rewrites applied to titles and abstracts to fish out links between diseases and alleles

Correspondence of molecules with allele structures is difficult.

• use blast to fiind closest allele match between pdb and allele sequence
• every pdb and allele residue has URI
• relate matching molecules
• relate each allele residue to the canonical allele
• annotate various residoes with various coordinate systems

This creates massive map that can be navigated and queried. Example queries:

• What autoimmune diseases can de indexed against a given allele?
• What are the variant residues at a position?
• Classification of amino acids
• Show alleles perturned at contacts of 1AGB

Summary of Progress to Date:
Elements of Approach in Place: Structure, Variation, transfer of annotation via alignment, information extraction from literature etc…

Nuts and Bolts:

• Primary source
• Local copy of souce
• Scripts transforms to RDF
• Exports RDF Bundles
• Get selected RDF Bundles and load into triple store

• Parsers generate in memory structures (python, java)
• Template files are instructions to fomat these into owl
• Modeling is iteratively refined by editiing templates
• RDF loaded into Neurocommons, some amount of reasoning

RDFHerd package management for data

neurocommons.org/bundles

Can we reduce the burden of data integration?

• Too many people are doing data integration – wasting effort
• Use web as platform
• Too many ontologies…here’s the social pressure again

Challenges

• have lawyers bless every bit of data integration
• reasoning over triple stores
• SPARQL over HTTP
• Understand and exploit ontology and reasoning
• Grow a software ecosystem like Firefox

The Microsoft Biology Foundation

As most of you may know, Microsoft – and in particular the folks at Microsoft (External) Research – have started to make major inroads into developing tools for scientists, be that in the area of scholarly communication with a repository offering as well as an ontology plugin for Word or in chemistry with Chem4Word, which is currently being developed by Joe Townsend, Jim Downing and Peter Murray-Rust here at Cambridge and the team at Microsoft External Research.

Now they have also announced a first version of the Microsoft Biology Foundation. From the announcement:

“The Microsoft Biology Foundation (MBF) is a language-neutral bioinformatics toolkit built as an extension to the Microsoft .NET Framework. Currently it implements a range of parsers for common bioinformatics file formats; a range of algorithms for manipulating DNA, RNA, and protein sequences; and a set of connectors to biological Web services such as NCBI BLAST. MBF is available under an open source license, and executables, source code, demo applications, and documentation are freely downloadable […]”

Now every time Microsoft gets involved in something like this, it is bound to generate discussion and debate, such as happened around Chem4Word (see here and links contained in this). I, for one, am happy about every constructive and open contribution to the canon of scientific tools available to the community and welcome the news.

Capturing process: In silico, in laboratorio and all the messy in-betweens – Cameron Neylon @ the Unilever Centre

I am not very good at live-blogging, but Cameron Neylon is at the Unilever Centre and giving a talk about capturing the scientific process. This is important stuff and so I shall give it a go.

He starts off by making the point that to capture the scientific process we need to capture the information about the objects we are investigating as well as the process how we get there.

Journals not enough – the journal article is static but knowledge is dynamic. Can solutions come from software development? Yes to a certain extent….

e.g. source control/versioning systems – captures snapshots of development over time, date stamping etc.
Unit testing – continuous tests as part of the science/knowledge testing
Solid-replication…distributed version control

Branching and merging: data integration. However, commits are free text..unstructured knowledge…no relationships between objects – what Cameron really wants to say is NO ONTOLOGIES, NO LINKED DATA.

Need linked data, need ontologies: towards a linked web of data.

Data is nice and well…but how about the stuff that goes on in the lab? Objects, data spread over multiple silos – recording much harder: we need to worry about the lab notebook.

“Lab notebook is pretty much an episodic journal” – which is not too dissimilar to a blog. Similarities are striking: descriptions of stuff happening, date stamping, categorisation, tagging, accessibility…and not of much interest to most people…;-). But problem with blogs is still information retrieval – same as lab notbook…

Now showing a blog of one of his students recording lab work…software built by Jeremy Frey’s group….blog IS the primary record: blog is a production system…2GB of data. At first glance lab-log similar to conventional blog: dates, tags etc….BUT fundamental difference is that data is marked up and linked to other relevant resources…now showing video demo of capturing provanance, date, linking of resources, versioning, etc: data is linked to experiment/procedure, procedure is linked to sample, sample is linked to material….etc….

Proposes that his blog system is a system for capturing both objects and processes….a web of objects…now showing a visualisation of resources in the notbook and demonstrates that the visualisation of the connectedness of the resources can indicate problems in the science or recording of science etc….and says it is only the linking/networking effect that allows you to do this. BUT…no semantics in the system yet (tags yes…no PROPER semantics).

Initial labblog used hand-coded markup: scientists needed to know how to hand code markup…and hated it…..this led to a desire for templates….templates create posts and associate controlled vocab and specify the metadata that needs to be recorded for a given procedure….in effect they are metadata frameworks….templates can be preconfigured for procedures and experiments….metadata frameworks map onto ontologies quite well….

Bio-ontologies…sometimes convolute process and object….says there is no particularly good ontology of experiments….I think the OBI and EXPO people might disagree….

So how about the future?

Important thing is: capture at source IN CONTEXT

Capture as much as possible automatically. Try and take human out of the equation as much as possible.

In the lab capture each object as it is created and capture the plan and track the execution step by step

Data repositories as easy as Flickr – repos specific for a data type and then link artefacts together across repos..e.g. the Periodic Table of Videos on YouTube, embedding of chemical structures into pages from ChemSpider…

More natural interfaces to interact with these records…better visualisation etc…

Trust and Provenance and cutting through the noise: which objects/people/literature will I trust and pay attention to? Managing people and reputation of people creating the objects: SEMANTIC SOCIAL WEB (now shows FriendFeed as an example: subscription as a measure of trust in people, but people discussing objects) “Data finds the data, then people find the people”..Social network with objects at the Centre…

Connecting with people only works if the objects are OPEN

Connected research changes the playing field – again resources are key

OUCH controversy: communicate first, standardize second….but at least he ackowledges that it will be messy….

UPDATE: Cameron’s slides of the talk are here:

Capturing Process

View more presentations from Cameron Neylon.

Data-Rich Publishing

I have been insanely busy recently with trips and papers and corrections and…etc…and only now have a bit of time to catch up with some of my feeds and people’s blog posts. One post which caught my eye was Egon’s recent blog post about data-rich or data-centric publishing, in which he argues strongly for a new kind of publishing: a publishing in which data is treated as a first class citizen and which allows/requires an author to not just publish the words of a paper, but his research data too and to publish it in such a way that the barrier to access by machines is low.

This reminded me of what I thought was a particularly tragic case, which I blogged about a while ago here. In this particular case, industrious researchers had synthesized an incredible 630 polystyrene copolymers and recorded their RAMAN spectra. Now this is more than a crying shame: a lot of work has gone into producing the polymers and recording the data. And I ask you (provided you are a materials scientist and have an interest in such things), when was the last time that YOU came across such a large and rich library of polymers together with their spectral data? And through no fault of their own, the only way these authors saw to publish their data was in the form of a pdf archive in the supplemental information.

Now Egon’s point was that newly formed journals – and in particular newly formed Journals of Chemoinformatics – have the opportunity to do something fundamentally good and wholesome: namely to change the way in which data publication is being accomplished and to give scientists BETTER tools to deal with and disseminate their data. This long and rambly blogpost is my way of violently agreeing with Egon: I believe that THIS is where an awful lot of the added value of the journal of the future will lie. This will be even more true, as successive generations of scientists will start to become more data savvy: last week I talked to a collaborator of ours who had just put in for some funding to train chemistry students in both chemistry and informatics: a whole dedicated course. Now once these students start their own scientific careers, they will both care and know about science and scientific data. And if I were a publisher, I would want to have something to offer them….